Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions

International Journal of Physics | Vol. 12, No. 3, March 2021 | pp. 17–24

DOI: 10.46882/2021/IJP/000131

Research Article

Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions

Names of Authors: D. W. Meyer¹, J. R. Weber²

Authors’ Affiliations:
¹ Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
² Physik-Department, Technische Universität München, Garching, Germany

Abstract: Maximising thermal dissipation metrics across low-dimensional heterostructures is an engineering priority for managing hotspots inside next-generation high-frequency field-effect transistors and optoelectronic microchips. This paper details molecular dynamics simulations aimed at quantifying thermal dispersion parameters and mapping acoustic phonon wavepacket scattering dynamics across graphene-boron nitride (Gr-hBN) lateral junctions. Atomistic lattices were constructed with the optimized Tersoff empirical potentials, containing varying structural configurations of boundary mismatch lines and localized point vacancy defects. Longitudinal and transverse acoustic phonon wavepackets were launched across a high-frequency grid centered between 2.0 THz and 12.0 THz. The computational models prove that high-frequency acoustic phonons (f greater than 6.0 THz) face severe diffuse scattering patterns at defective junction planes, dropping the calculated transmission coefficient from 0.78 down to 0.16. This thermal resistance stems from localized strain profiles and interface-confined vibrational resonance modes. The composite interface thermal conductance fell by 52.0% when boundary defect percentages were adjusted from 1.0% to 5.0% at 300.0 K, revealing atomic constraints for nanoscale heat management.

Keywords: Thermal conductance; phonon wavepacket; molecular dynamics; interface defects; graphene; boron nitride

Manuscript Timeline: Received: December 14, 2020; Revised: January 20, 2021; Accepted: February 08, 2021; Published: March 15, 2021

Citation: Meyer, D. W., & Weber, J. R. (2021). Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions. International Journal of Physics, 12(3), 17–24.

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